Channel Model Ad Hoc Report Presented by Duane Remein (Huawei)
Activities Held 7 Teleconferences since San Antonio meeting Scheduled on Thursdays 5:30 PM (EST) Average 8 attendees Discussion focused on Parameter List (introduced in San Antonio) Topology models Slide 2
Parameter List Significant progress on DS tables Most parameters defined Good progress on US tables Most significant parameters defined Some outstanding work on newer parameters (such as Amplitude variation) Getting input from operators, these parameters are somewhat unique to a given plant
Topologies Several defined Each paired with a parameter table Some may be associated with the same parameter table Priority Topology Para Table High Node +3 (digital EPON distribution) A Med Node +0 (Last Amp) B Low Node +0 (All Passive) B Low Node +3 (analog EPoC distribution) C Info EPoC Only (no HFC) D
Topology Example Node +3 (digital EPON distribution) Opt TRx HFC FCU FCU EPON OLT FCU FCU Variations Node +1 (single amp) Node +2 (not shown) Do we need to define a Node+N topology? How big is N? Details needed: Diplexer connecting EPoC to COAX Topology parameters needed: 1. Optical reach of HFC networks 2. Optical reach of EPON networks 3. Channel loading of HFC networks (can all digital be assumed?) 4. Amplifier spacing; typical and max. ex: typical 800 ft. maximum 1500 ft. 5. Feeder cable types 6. Drop Cable types & reach Slide 5
Plans Complete parameter lists Finalize Topology models to be addressed Complete definition list of all terms in parameter list
THANK YOU
Ad Hoc Purpose & Scope Channel Model Purpose Purpose 1: To facilitate the evaluation of multiple PHY modulation proposals for use in 802.3bn Purpose 2: To facilitate the selection of a range of PHY parameters within the selected PHY proposal to allow adaption to changing PHY conditions within the coax environment Channel Model Scope Model should be limited to the minimum set of critical parameters necessary for above purposes. Slide 8
Tools Discussed Tools Excel for input and static modeling Parametric data tables Quick check tool to assess proposals GNU Octave if we need to adopt a simulator Results from other tools OK if input consistent with parametric data tables Slide 9
Parameter List (1 of 2) DS US Channel Param Min Max Nom Min Max Nom Units Notes Noise Power Ratio Parameters affected: QAM Level and db/db dynamic range Composite Channel Noise details tbd Microreflections Parameters affected: Cyclic Prefix duration, Subcarrier Bandwidth 0.5 μsec dbc sub-parameter limits tbd, 4 buckets OK <= 1.0 μsec dbc <= 1.5 μsec dbc > 1.5 μsec dbc Group Delay Ripple Parameters affected: Cyclic Prefix duration, Subcarrier @ lower channel ns/mhz Bandwidth @ center Channel ns/mhz Should be frequency dependent, 2-3 frequency ranges, @ high Channel ns/mhz relative to channel size Impulse Noise Wide band, intermittent in time duration ns Parameters affected: FEC Overhead, Interleaver? amplitude dbc exact sub-parameters/units tbd periodicity khz(?) Burst Noise Narrow band noise, intermittent in time duration ns exact sub-parameters/units tbd amplitude dbc periodicity khz(?) frequency band MHz such as LTE Slide 10
Parameter List (2 of 2) DS US Channel Param Min Max Nom Min Max Nom Units Notes Sub-Carrier to Discrete Interference This parameter needs more detail, i.e. how many subcarriers Percent S-Cs with 0dBc < SIR < 5dBc % below XdB CIR? See channel parameters sent Nov Percent S-Cs with 5dBc < SIR < 10dBc % 2nd, 2:06pm Central Time to reflector. This parameter is open to discussion. exact number of subparameters Percent S-Cs with 10dBc < SIR < 15dBc % tbd Percent S-Cs with 15dBc < SIR < 20dBc % Percent S-Cs with 20dBc < SIR < 25dBc % Amplitude Ripple Should subcarriers have different QAM? db/mhz This parameter is likely be expanded into 3-4 entries Should be added to CPL, can sub-carrier tracking loops Carrier Hum Modulation follow 60/120 Hz hum? Defines short term variations due to active elements in the dbc channel (e.g., amplifiers), may or may not be included Transit Delay us Both upstream and downstream Channel Loading (outside EPoC channel) Multiple tables may need to be generated based on the specific topology. Notes Phase Noise limites are included in the transmitter and receiver specifications. Shaded cell to remain empty (not needed) Empty columns to be removed prior to baseline Slide 11